Improvement in sled-brakes



L; H. THOMAS.

Sled-Brake.

| l I I I l Jizvcnfo r.-

N'FETERS. FHOTO-UTHOGRAPHER. WASHINGTON. B C,

Patented Aug 1. 1865.

UNITED STATES PATENT OFFICE.

LEVI H. THOMAS, or WATERBURY, VERMONT.

IMPROVEMENT IN SLED-BRAKES.

Specification forming part of Letters Patent No. 49,173, dated August 1,1865.

To all whom it may concern:

Be it known that I, LEVI H. THOMAS, of the town of Waterbury, in thecounty of VVa-shington, State of Vermont, have invented certain new anduseful Improvements in Sleigh or Sled Brakes; and the following is afull, clear, and exact description of the same, reference being bad tothe accompanying drawings, making a part of this specification, inwhicha Figurel showsa longitudinal section through the sled. Fig. 2shows an under-side views of the sled, with the sliding frame andvibrating bar.

The object ot' my improvement is to equalize the holding back betweenboth of the runners and allow either of the prongs or hooks to let goand pass over obstructions or equalizetheir hold in the track.

My invention consists in the reciprocating selfadjusting bar attached tothe sliding lrame, in combination with the dogs or hooks to take hold ofthe ice or snow, so that when one of the runners is upon iceorahard-beaten snow-path and the other is running upon a more yieldingsubstance the reciprocating bar will allow the dogs to adjust themselvesto the density of the substance they are brought in contact with, oreither one of them throw up so as to pass over an obstruction, and atthe same time put the burden to be borne upon its fellow.

To enable others skilled in the alt to make and use my invention. I willdescribe it in de' tail,'referring to the drawings, and to the lettersmarked thereon.

To any 0rdinar-ilyconstructed sleigh or sled I place, between theravesAA, asquareframe. The side pieces, B B, to which the pole or tongue0 is attachcd,are of the samethickness as the raves, and are made toslide on the beams a a, and are held in by cross-bars b b, which extendunder the inner edges of the raves, so as to allow the frame to slide-afew inches back when the load presses forward onto the team, as indescending a hill. To the under side of the frame is secured, to thepieces B B, across-brace, D D, which lies in between the sledbeams a a.To the center of this crossbrace is pivoted an evener or vibrating bar,E, which is held firmly against stop-pins 00 when the draftis on thesled; but when the weight of the load forces the frame back thevibrating lever or bar E will have motion enough to relieve either oneof the dogs or prongs d (1,

they come in contact with, or will entirely relieve itself, one at atime, to pass over an obstruction. The one being relieved necessarilyforces the other down to its fullest capacity, which holds the load, butrelieves the sled and team from the shock which would otherwise occur.

To prevent the movable hooks e e from sticking and holding in a positionthat would not allow them to catch hold, I put a pin, ff, in the runnersF F just forward of the hooks.

The advantages of my improved sled-brakes over others are that thepressure of the brakes is equalized to the density of the surface theycome in contact with, and when one of the brakes meets with anobstruction byrelieving itself puts the whole work of both onto itsfellow for the time being.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is-

1. The vibrating self-adjustingbar attached to the sliding frame, thesame being connected with the levers, and so operating the prongs ordogs that they will adjust themselves to the density of the substancethey come in contact with.

2. Placing the pins f f in suchaposition with the movable hooks e c astoalways insure their taking hold to break theforce of the load whenpressing forward.

L. H. THOMAS.

Witnesses: J. B. WoonRUFF, J. S. ADAMS.

